【作者】 渠翠平； 关德新； 王安志； 金昌杰； 吴家兵； 王纪军； 倪攀； 袁凤辉；

【Author】 QU Cui-ping1,2 GUAN De-xin1 WANG An-zhi1 JIN Chang-jie1 JIN Chang-jie1 WANG Ji-jun1 Ni Pan1 Yuan Feng-hui1 (1 Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China , 2 Graduate University of Chinese Academy of Sciences, Beijing 100049, China)

【机构】 中国科学院沈阳应用生态研究所；

【摘要】 利用内蒙古科左后旗草甸草地2000—2006年MODIS的8d合成NDVI(归一化植被指数)资料和逐日气象资料,分析了NDVI的季节变化和年际变化特点以及NDVI与气象因子的关系,发现如下主要规律:季节变化过程中,草甸草地较高的地下水位使得降水量对NDVI的影响低于水汽压的影响;积温和累积降水量共同控制着各年草地的返青速度,草地增长期(6、7月)的降水量对NDVI年最大值的影响比年总降水量更显著;时滞分析表明,水汽压持续影响到之后约12d的NDVI,平均气温的时滞为11—15d,降水量对NDVI影响的累积时滞双重效应可达36—52d.更多还原

【Abstract】 Using MODIS 8-day composite NDVI data and Horqin daily meteorological data from 2000 to 2006, the annual and inter-annual variations of NDVI were examined, and the relations between NDVI and meteorological factors were also discussed. The results showed that the seasonal variation of NDVI demonstrated a stronger relationship with water vapor pressure than with precipitation, when the meadow have high underground water level. The inter-annual turning green period was significantly affected both by the cumulated temperature, and by the cumulated precipitation. Annual maximal NDVI was predominantly influenced by precipitation in the peak of growing season(June and July).The analysis of time lag effect indicated that water vapor pressure had a prominent impact on NDVI lasting about 12 days; the correspondence between NDVI and mean temperature had a marked lag between 11and 15 days. NDVI tied up with precipitation total before 36—52 days, containing both time lag effect and cumulating effect.更多还原